This chapter argues that affirmative action is sometimes justifiable. ‘Affirmative action’ refers to policies beyond anti-discrimination law that directly regulate selection procedures to enhance the representation of members of various socially salient groups, such as those based on gender, race, and ethnicity. The chapter outlines an argument in support of affirmative action by distinguishing three prominent forms of wrongful discrimination and by showing that affirmative action is the appropriate response to the past and present wrongful discrimination suffered by members of socially salient groups. It also adds a second argument for affirmative action that appeals to the importance of enhancing diversity and social integration. The chapter then tackles several objections and reflects on the implications of these arguments for the design of affirmative action policies.